North Carolina is trying to recruit girls for careers in engineering not only to fill anticipated vacancies but also because hiring more women could make the roads safer.

The North Carolina Department of Transportation (DOT) is using newspapers, masking tape and a competitive spirit to get more young women interested in engineering.

The agency is hosting a series of events where girls in high school and junior high can meet and work with the department's women engineers. Each engineer is assigned a table of students and tasked with constructing the tallest building they can with just five sheets of newspaper and five pieces of masking tape. The teams are judged, not just on how tall their buildings are, but how durable they are too. For instance, can they survive earthquakes (the table being rocked beneath them) and high winds (an electric fan set beside them)?

It is one of many activities at the gatherings, which also include presentations on what engineers do. Panelists discuss why they chose engineering, what is required academically to get into the field and what types of jobs are available. North Carolina is hosting four such events over a month, with roughly 200 students expected to participate. "All of the girls there were awestruck [by the presentations]," said Gail Herring, who coordinates the programs for the North Carolina DOT. "The purpose is to encourage more women to go into engineering, because the number of jobs in STEM (science, technology, engineering and math) are going to double in the near future. We need more women and minorities to consider this opportunity."

For the North Carolina DOT, getting girls excited about engineering is important for its future. Like many transportation agencies -- and public agencies in general -- the department faces a future where job openings could far outnumber qualified applicants. Boosting interest among women, who are vastly underrepresented in the transportation field, is one way to address that issue. And, experts say, increasing the number of women in the workforce could improve the quality of transportation systems, too.

The lack of women in transportation careers is apparent throughout the industry, from mechanics to pilots to executives, said Marcia Ferranto, the president and CEO of the Women's Transportation Seminar (WTS), an international group whose local chapter co-hosted two of the North Carolina events. Take, for example, the number of women in top leadership positions, she said. Although the numbers have been growing, only eight states -- Delaware, Louisiana, Massachusetts, Mississippi, New York, Pennsylvania, South Carolina, Vermont and Washington -- have transportation departments headed by women. Only two of the 17 U.S. secretaries of transportation have been women. Even most private transportation companies are headed by men. "Until we get more women in these positions," Ferranto said, "it's harder for us to attract women into the field."

There are many other factors that discourage women from going into transportation as well, according to Ferranto. Many women who started off in the industry have not advanced, she said. They may have opted for another career because they could not advance in transportation or because their workplaces were not family-friendly.

And convincing women to study engineering is no guarantee that they will stick with a job in male-dominated workplaces. In engineering generally, women make up a fifth of college graduates with engineering degrees, but they only account for 11 percent of engineers in the workforce, according to a 2012 study commissioned by the federal government.

WTS and the U.S. Department of Transportation have started a program called "Transportation You" aimed at girls ages 13 to 18 to explore transportation careers. Ferranto expects that more state and local transportation agencies will start similar programs, as public agencies have been ahead of private industry in addressing the gender imbalance.

The lack of women engineers designing transportation systems can lead to real world problems, said Harvard University public health researcher Anne Lusk. Early air bags in cars injured or killed women and children because they were designed to protect men. In fact, the federal agency that evaluates crash safety for vehicles first started using smaller, "female" dummies in its compliance tests in 2003. Even some bus shelters discourage women from using them by not offering multiple exits, she said.

Lusk, whose work focuses on cycling, said male dominance in transportation engineering has led to more dangerous traveling experiences for women. For instance, she said, her research found that bike lanes physically separated from traffic are safer than painted bike lanes on the side of the road. Women, in particular, favor bike lanes cordoned off from vehicle traffic, research has shown. But for years, U.S. transportation planners shunned cycle tracks.

One of the big reasons for that, Lusk said, is that the teams that developed the industry's bike infrastructure standards were dominated by men. When the American Association of State Highway and Transportation Officials (AASHTO) produced those standards in 1991 and 1999, its teams were 91 and 97 percent male, respectively. The cycling guidelines were updated again in 2012, but they again did not include protocols for protected bike lanes. (AASHTO officials did not respond to requests for comment by press time.)

There are other ways a male-centered approach discourages women from biking, Lusk said. Environmentally friendly building standards often call for places to store bikes. But, in many cases, those storage spaces are "bike cages," which discourage women cyclists. They often have only one exit, raising safety concerns. And many require cyclists to lift their bikes, which discourages women who tend to have heavier bikes and less upper body strength, Lusk said.

Even the time cyclists have to cross intersections on a green signal can reflect the biases of men engineers, she said. Research shows women take longer to get through an intersection than men. They generally don't have as much leg strength as men. But women's attire and the weight of their bikes also make them slower than men.

More women in the transportation industry, she said, could help address those issues. "I think it would be lovely if all young girls saw the positive impact they could make on transportation infrastructure if they were in the design world."